Options are limited for repurposing the old Rainbow Powerhouse since it’s located within an active hydropower operation, but locals are continuing their effort to save the century old structure from demolition.

In today’s dollars, it would cost about $20 million to build a structure equivalent to the powerhouse on the Missouri River that has significant architectural and historical important, Ellen Sievert, the former city-county historic preservation officer, said during a public meeting in late October.

“No one wants to waste the effort that went into building the Rainbow powerhouse,” she said, and considers it 56,000 square feet of opportunity.

Public meeting is Thursday on repurposing the Rainbow Powerhouse

NorthWestern Energy owns the powerhouse and the company commissioned a feasibility study, which was a major financial investment in the effort to repurpose the building, said County Commissioner Jane Weber.

During the October meeting, Sievert, Weber and others who are working to preserve the powerhouse presented an update on their efforts and Anthony Houtz from CTA Architects Engineers presented the findings of the feasibility study.

“There’s more value in this structure than meets the eye or you might expect,” Houtz said.

About 25 people attended the meeting, including city and county officials, state parks officials and staff from Sen. Jon Tester’s office, among others.

Construction on the 80-foot wide and 326-foot long powerhouse began in 1909 and was completed in 1910, along with the dam and the power line. Electricity was first transmitted to Butte in 1910, according to a fact sheet from the HPAC.

Additions were completed in 1916 and 1930, Houtz said of the steel and brick structure.

“You can tell they spent some time and took care when they designed this,” he said of the architectural details of the Rainbow powerhouse.

Around 2008, plans for replacing the hydroelectric facility were beginning and a core group of people started working to find someone or something to repurpose the facility.

Those efforts are accelerating now since a federal agency has placed a July 2019 deadline on local efforts to have a viable plan in place.

That core group included Sievert, Weber and Peter Jennings, of the Arvon Block project; and Pete Brown of the State Historic Preservation Office, Micuda said.

Others have been involved as well and the powerhouse came offline in 2013 when the new powerhouse became operational. The facility ownership changed from PPL to Northwestern Energy in 2014.

Mary Gail Sullivan, manager of environmental permitting and compliance at Northwestern Energy, said “the passion is infectious,” in relation to the group attempting to repurpose the powerhouse.

She said the company is committed to “doing the right thing” and looking for partners, but they are limited for redevelopment options by federal regulations.

Dam safety is the top priority, she said, since the old powerhouse is on the same site as an active hydropower operation.

Northwestern Energy is preparing a plan for demolition, Sullivan said, but are continuing to support local efforts to find another use for the powerhouse that will be safe and compatible with existing operations.

Weber said the local historic preservation group has a good relationship with Northwestern Energy, “but we do have a time clock ticking.”

One of the challenges is that almost nothing in the building meets current codes since it’s more than a century old and was built for industrial use, not regular human use, Houtz said. But, the way it’s constructed helps code compliance efforts since it allows flexibility in upgrading the places that would need upgrading, he said.

“No matter what we do, we want to continue to tell the the history of the building,” he said.

Jennings said a cryptominer from California visited Great Falls last week to look at the powerhouse.

Considering options for the structure to be used as a data center of some sort and a local group has floated the idea of a greenhouse operations. Water is available, though there would be the question of water rights, and the building isn’t insulated.

A potential idea solution would be co-locating a data facility and a greenhouse operation to take advantage of waste heat from the data center and shared costs.Tax credits are also an option for a potential developer.

Weber said that not many people have had the opportunity to go inside the powerhouse, but many have enjoyed viewing it from the River’s Edge Trail.

Since a brew pub with condos is off the table, Weber said they want to find a utilitarian use that will allow the community to continue to appreciate the powerhouse from the outside.

Weber said they’re reaching out through national channels and other avenues in the hopes of finding a user for the building and also funding for a viable use.